Locomotives are complex systems with numerous subsystems, with each subsystem being interdependent on other subsystems. An operator is aboard a locomotive to ensure the proper operation of the locomotive and its associated load of freight cars. In addition to ensuring proper operations of the locomotive, the operator also is responsible for determining operating speeds of the train and forces within the train that the locomotives are part of. To perform this function, the operator generally must have extensive experience with operating the locomotive and various trains over the specified terrain. This knowledge is needed to comply with prescribeable operating speeds that may vary with the train location along the track. Moreover, the operator is also responsible for assuring in-train forces remain within acceptable limits.
Based on a particular train mission, it is common practice to provide a range of locomotives to power the train, depending on available power and run history. This leads to a large variation of available locomotive power for an individual train. Additionally, for critical trains, such as Z-trains, backup power, typically backup locomotives, is typically provided to cover the event of equipment failure and ensure that the train reaches its destination on time.
When operating a train, train operators typically call for the same notch setting based on previous operations of like train over the same track, which in turn leads to a large variation in fuel consumption since the trains are not exactly alike. Thus the operator cannot usually operate the locomotives so that the fuel consumption is minimized for each trip. This is difficult to do since, as an example, the size and loading of trains vary, and locomotives and their fuel/emissions characteristics are different.
Typically, once a train is composed and once it leaves the rail yard, or hump yard, the train dynamics, such as fuel efficiency versus speed, maximum acceleration and track conditions as well as track permissions, are generally known to the train and crew. However, the train operates in a network of railroad tracks with multiple trains running concurrently where tracks in the network of railroad tracks intersect and/or trains must navigate meet/pass track along a route. The network knowledge such as the time of arrival, scheduling of new trains and crews, as well as overall network health, is known at a central location, or distributed place, such as the dispatch center but not aboard the train. It is desirable to combine the local train knowledge with global network knowledge to determine an optimized system performance for each train in a railroad network. Towards this end, in a railroad network, operators would benefit from an optimized fuel efficiency and/or emissions efficiency and time of arrival for the overall network of multiple intersecting tracks and trains.